Gravitational waves are ripples in the curvature of spacetime that are generated by gravitational interactions of certain varieties. These are propagated a waves outward from their source at the speed of light. These gravity waves originated from a pair of merging black holes. The possibility of such waves was first discussed in 1893 by Oliver Heaviside.
However it was Hneri poincare that first proposed gravitational waves in 1905. Gravitational wave astronomy is a branch of observational astronomy that uses these gravitational waves to collect observational data in the binary star system.